Evaluation Metrics. To evaluate the quality of the HDR images, we used the popular HDR-VDP2 [1]} metric, and adopted the means squared error (MSE) metric as used in other works [2]}, [3]}. We normalize the predicted and reference ground truth HDR images [4]}. Then to account for the human visual system's sensitivity to lighting at different luminance values, we apply perceptual uniform (PU) encoding to calculate PU-PSNR and PU-SSIM metrics [5]}, to further evaluate the accuracy of the HDR images.
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